Ultra wide angle zoom lens compatible with digital SLR cameras with a 35mm full frame image sensor.
Sigma designed and produced the first wide-angle zoom lens, the "zoom gamma 21-35mm F3.5-4", in 1979. Sigma has since introduced a number of wide angle zoom lenses. The SIGMA 12-24mm F4.5-5.6 II DG HSM is the successor of the SIGMA 12-24mm F4.5-5.6 EX DG ASPHERICAL / HSM which was launched in November 2003. This ultra wide angle zoom lens is ideal for digital SLRs with a 35mm full frame image sensor and incorporates the latest optical design.
Superior image quality
The ultra wide angle zoom lens is possible due to large diameter of the front lens. Four FLD ("F" Low Dispersion) glass elements, which have performance equal to fluorite, and one SLD (Special Low Dispersion) glass element provide excellent correction of color aberration. Three glass mold elements and one hybrid aspherical compensate for all types of aberration and ensure high optical performance.※ FLD glass is the highest level low dispersion glass available with extremely high light transmission. This optical glass has a performance equal to fluorite glass which has a low refractive index and low dispersion compared to current optical glass. It also benefits from high anomalous dispersion. These characteristics give excellent correction for residual chromatic aberration (secondary spectrum) which cannot be corrected by ordinary optical glass and ensures high definition and high contrast images.
Super Multi-Layer Coating
Due to the ultra wide angle, the front of this lens is very large. Sigma's Super Multi-Layer Coating reduces flare and ghosting which could otherwise create problems when extraneous light hits the lens' front element. It also provides sharp and high contrast images throughout the entire zoom range.
Superior peripheral brightness
The design of front lens group minimizes light fall off and increases peripheral brightness.
The wide-angle of view produces striking images with exaggerated perspective, enabling photographers to emphasize the subject.
Incorporation of four aspherical lenses provides a compact construction with a diameter of 85mm (3.3"), overall length of 120.2mm (4.7") and weight of 670g (23.6oz.). The compact construction makes this lens ideal for travel photography.
Quiet and high speed autofocus
Incorporation of HSM (Hyper Sonic Motor) ensures quiet and high speed autofocus, while allowing full-time manual focus override.
Inner focusing system
This lens incorporates an inner focusing system, which eliminates front lens rotation which also minimizes fluctuation of aberration caused by the focusing system.
This lens is equipped with a Petal-type hood to block out extraneous light and reduce internal reflections.